Hawaii is a unique state, with abundant natural resources that can be used to produce energy. In the 21st century, the Hawaiian Islands have taken concrete steps to support renewable energy sources, such as wind, sun, running water, bioenergy, and geothermal energy. To make it easier for biofuel producers to lease state land, Hawaii passed HB 3179. Acts SB 3190 and HB 2168 authorized special-purpose income bonds to finance a solar energy installation on Oahu and hydrogen generation and conversion facilities at the Hawaii Authority's Natural Energy Laboratory on the island of Hawaii. SB 988 allowed the Hawaii Public Utilities Commission to establish a reimbursement for photovoltaic systems, and HB 2550 encouraged net metering for residential and small commercial customers.
Partnerships between the United States Department of Energy (EERE), the State of Hawaii, Hawaiian Electric Company, and Phoenix Motorcars have been formed to further renewable energy initiatives. The Hawaii Authority's Natural Energy Laboratory is a test site for experimental renewable energy projects. It was originally built to test ocean thermal energy conversion (OTEC) and later became a commercial industrial park. Cellana produces oil from algae at a 2.5-hectare (6.2-acre) research site in Kailua-Kona, on the island of Hawaii. Cellana (formerly HR BioPetroleum) worked with Royal Dutch Shell on a pilot facility to grow algae on land leased by the Hawaii Authority's Natural Energy Laboratory, on the west coast of the island.
To encourage residential and small commercial customers to use renewable energy sources, Hawaii requires solar water heaters for new homes, except for those in areas with scarce solar energy resources or homes that use other renewable energy sources or gas water heaters on demand. Hawaii has several biomass power plants, including the 10 MW Honolulu International Airport emergency power plant, the 6.7 MW green energy agricultural biomass conversion plant on Kauai, and the 6.6 MW Honua waste power project on Oahu. In partnership with the Hawaii National Marine Renewable Energy Center, connected to the Hawaii Natural Energy Institute and the University of Hawaii, wave buoy manufacturers can test the performance of their wave buoy designs. Hawaii began wind energy research in the mid-1980s with a 340 kW turbine in Maui, the 2.3 MW Lalamilo Wells wind farm on Oahu, and the 9 MW Kamaoa wind farm on the island of Hawaii. Solar energy in Hawaii has grown rapidly over time and now supplies more and more energy to the state. The founders of Pacific Biodiesel, Bob and Kelly King, grow sunflowers and other crops on their Maui farm as part of a community model of sustainable agriculture.
Renewable natural gas(RNG), also known as biogas, is a form of gaseous energy created from the decay of organic matter such as wastewater, biosolids, food waste or animal manure under anaerobic conditions or in conditions without oxygen.
The overall coal industry has been dwindling as other energy sources become more affordable; now that the last shipment of coal has been delivered to the island, Hawaii is closer to its renewable energy goals. Batteries that store excess renewable energy and are discharged when that energy is unavailable extend utility and improve the predictable availability of renewable sources. In many cases, including the Western Kauaʻi energy project being carried out in Kauaʻi, solar energy is used to pump water “upstream” from the lower reservoir to the upper reservoir making these facilities 100% renewable.